In the application of flowable media on a substrate, particularly when very small amounts of the flowable medium are to be uniformly applied, it is known to use a roller partially dipping into a trough containing the medium, so that the turning roller entrains the medium in its motion. In order to control the thickness of the layer adhering to the surface, it is known to provide stripping wipers. It is also known to first transfer the medium to be applied by means of a dosage roller to an applicator roller, which then transfers the medium to the substrate to be treated. Furthermore, it is known to use roller wipers and other application devices magnetically pressed against the substrate, during printing as well as during coating.
Particularly when small amounts of medium are applied, the interplay between the roller dipped into the medium or receiving the medium and the applicator roller, as well as the proper magnetic pressure towards the web of material, becomes very important.